[alexander_busek]

I think the gradient in oxygen pressure causes movement of oxygen molecules towards equilibrium independent of convection. But it’s been many years since I studied this, so please forgive me if what I say is wrong.

What you're saying isn't wrong, per se, but it isn't the only - or even the dominant - factor involved.

Are you denying that convection could also play a role? Are you denying that convection could possibly even greatly overshadow mere diffusion?

My wife's nagging me while I drive a car will not influence my blood alcohol level - they are two independent factors. Both affect my driving ability. Given various circumstances, one, or both, or none of those two factors could be responsible for my causing an accident.

Regards,

P.S. There could even be a slight/powerful positive or negative correlation between two or more factors - i.e., they could be weakly/strongly coupled. Science is complicated!

[going hot]

My wife's nagging me while I drive a car will not influence my blood alcohol level - they are two independent factors.

There may be a causational factor involved, if your wife's nagging drove you to drink, your blood alcohol would certainly go up, and thus affect your driving.

YVW :-)

[reasonisfaith]

Which force overcomes another force depends on the state of the system at any given time. Of course oxygen diffusion can potentially overcome convection.

If you look carefully at my comments, you’ll recognize no denial of the effects of convection.

Science most complicated when combined with politics, as in the case of “global warming.” So complicated, it’s no longer science but pure politics.